Expansible hone



D. A, WALLACE l*2,312,011

EXPANSIBLE Hows Filed March 31,!1939 QN sm x y; "x/I Patented Feb. 23, 1943 EXPANSIBLE BONE David A. Wallace, Betr-oit, Mich., assigner to Chrysler Corporation, Highland Park, Mich., a

corporation of Delaware Application March 31, 1939, Serial No. 265,109

(Cl. 51184.l)

s claims The' present invention relates to the art of finishing surfaces such as cylindrical bores and comprises improvements in the structure of expansible hones and the thereof.

The invention comprises an expansible honing tool including a plurality of abrading elements, the tool being so constructed and arranged that the diameter of the tool may be increased after insertion of the tool into a bore by the application of fluid pressure whereby the abrading elements are held against the surface of the bore under fluid pressure, and in which the diameter of the tool may be reduced automatically in response to the release of fluid pressure whereby the tool may be withdrawn from the bore and inserted in another bore to be finished. The invention comprises the use of resilient, fluid-impervious expanding members operated by fluid pressure whereby even pressure may be exerted against the abrading elements throughout the extent of the work surfa'cein order that a uniform finish may be accomplished. The principal object of the invention related above is achieved by simple,

I easily manufactured and assembled means.

Other objects and advantages of the invention will be apparent from a study of the following specification and accompanying drawing, wherein like numerals refer to like parts throughout. In the drawing Fig. 1 disclosesa preferred form of my invention in operation; Fig. 2 is a: horizontal section taken alongline 2-2 of Fig. i; and Fig. 3 is a horizontal section, similar to Fig. 2, of a modifled form of hone. l i

In Figs. l and 2 there is disclosed a core struc- 'ture I0 comprising a s'tem I I and a body I2 having an integral flange I3 and a threaded shoulder I4. The flange I3 is at one end of the body portion I2 and a collar I5 of substantially the same diameter is slidably fastened to thelower end of the body I2 by a key I8. The flange I3 forms a fixed mounting means for one end of a hollow, resilient, fluid-impervious, substantially cylindrical expanding member I1 and the collar I5 forms a sliding mounting member for the other end of the exmeans of operation pander Il. The relatively thin end portions of the l vertically in order to accommodate such radialv whereby a fluid may be forced through the interior of the core structure into the interior of the expanding member. Such fluid may be admitted through a running gland 25comprising a non-rotative collar 26 mounted between rotative collars 21 and 28 fixed to the stem I I.r The uid may be forced through a pipe 30 into an annular space 3| communicating with the inlets 22, which space is provided in the interior surface of a ring 33 mounted between the stem I I and the running collar 26, and held in position by packing members 34 and 35 The pipe 30 may be connected to a source of fluid pressure (not shown)v by a resilient connection permitting vertical movement of the tool, and since the stem I I is free to rotate within the collar 25 the annular groove 3| will be at all times in communication with the interior o f the core structure. y

The expander Il preferably comprises a substantially thick wall of fluid-impervious material such as soft rubber cured to a self-sustaining but resilient state. A plurality of rigid mounting bars 40 are imbedded in the wall of the expander, the bars being preferably equally spaced about the circumference of the expander and extending longitudinally thereof from a` point adjacent the collar I3 to a point adjacent the collar I5. Abrading elements 4I are fixed to the mounting bars 40 so a's to protrude beyond the surface of the expander Il, the abrading elements being preferably long and narrow and being formed ofarticial material or natural stone commonly used for honing purposes. The surfaces of the mounting bars 40 may be adhered to the adjacent surfaces of the member Il by any well-known process such as vulcanizatlon.

\ Fig. 1 shows the honing member inserted within the cylindrical bore 45 of a cylinder block 46 and illustrates the use of the tool. The normal diameter of the tool (from the outer surfaces.. of diametrically opposite abrading elements) is preferably slightly less than the internal diameter of the bore 45 when the tool is in normal or nonexpanded ccnditionso that the tool may be inserted in the bore without dimculty. When the w01 is in position num may/be adnntted to the interior of the expander I1,/whereupon uniform pressure will be exerted throughout the interior 'of the expander and each of the expanding elements will be caused to move radially outward to substantially the same extent under substantially vthe same prssure. The tool may now be rotated and vertically reciprocated, as is usual in the practice of finishing cylindrical bores. When the operation has progressed to a suicient extent the fluid pressure may be released whereupon the expander I1 will automatically contract, permounting bars Il in order to reduce the amount of material necessary.

In Fig. 3 the expander l1 isy shown as being f formed of a substantially thin wall of resilient material, the outer surfaceof which is substantially cylindrical but which isprovided 'with a plurality of inwardly extending corrugations 50, to the outer surfaces yof `which lare bonded the mounting bars 40. When fluid pressure is exerted against the interior surface of the form shown in Fig. 3, the abrading elements Il will be moved outward uniformly under, uniform pressure, and, in addition, the sides of the mounting bars Il! will be'strongly gripped by the materialcomprising the corrugations 50 due to the exertion of pressure against ythe walls of the corrugations. l

Having illustrated and described several embodiments of my invention it should now be apparent to those skilled in the art that the vinvention permits of various modiflcationsin arrangement and details. All such modications as come within the scope of the following claims are considered a part of my invention.

I claim:

`1. An expansible hone for use in finishing cylindrical bores comprising a corestructure having an inlet and an outlet for the passage of fluids therethrough, a running gland rassociated with said core structure andhaving a fluid passageway communicating with the interior of said core structure, a substantially cylindrical, resilient, hollow, fluid-impervious member mounted on said core structure and Vsurrounding the outlet from said core structure, an abrading element supportmovable therewith kas said membery is expanded by fluid pressure transmitted through said fluid passageway, and a honing stone fixed to said bar and protruding beyond the surface of said member. Y a

2. An expansible hone for use in finishing cylindrical bores'comprlsing acore structure having an vinlet and an outlet for the kpassageof fluids therethrough, a running gland associated with said core structure and having a fluid passageway communicating with the interior of said core structure, a substantially cylindrical, re-

silient, hollow, fluid-impervious member mounted on said core structure and surrounding the outlet from said core structure, a plurality of abrading element supporting bars imbedded in the wall yof said member and movable therewith as said member is expanded by fluid pressure transl radial directions by expansion and-,contraction thereof in response to fluid pressure therein, said elements being spaced about the surface of said shell and extending substantially longitudinally thereof and parallel to the `longitudinal axis of said core structure.` 4.,'An expansible hone for use Ainflnishing'cylindrical bores comprising a core `structure having an inlet and an outlet, for the passage of fluids therethrough, 'a thick-walled, cylindrical shell of soft rubber mounted on said corestructure and surroundingthe outlet from said core structure, a plurality of rigid'mounting bars imi bedded inthe wall of said shell, and a plurality of abrading elements carried by'saidbars and ex-v tending beyond the `surfaceof said shell, said bars and elementsV being movable inradialdirecying lbar imbedded in the wall of said member andV tions by the expansion and contraction of said shell in response to fluid `pressure therein;

5. An'expansible hone for use in'flnishing cylindrical bores comprising Ya core structurelhaving an inlet and an outlet for the passage of fluids therethrough, a thick-walled,` cylindrical shell of softl rubber mounted `onsaid core structure and surrounding the outlet'from said .core structure, a plurality of rigid mounting 'bars f imbedded ir.

the wall of said shell, and a plurality of abrading elements carried by said bars and extending be.-

yond the surface ofsaid shellt/saidbars and elel ments being movable in radial: directionsby the expansion and contractioniof saidfshell in 'response to fluid pressure therein, said bars and elements extending longitudinally of said shell.

6. An expansible hone for use in finishing cylindrical bores comprising a core structurehav- 'ing an inlet and an outletfor the passage of fluids therethrough, a thin-walled, vcylindrical shell of soft rubb'er mounted on said :core structure and surrounding said outlet, said shell having a plurality of inwardly extending longitudinal corrugations, a mounting `bar bonded to the outer surface of each of said corrugations, and 

